Viber is one of the must have for IOS device. The app work perfectly smooth an have easy to use interface which lets you make free calls to other iphone and android devices . The viber calling is smiler to your GSM calls, the app uses your phone book contact to recognize which of your contact installed viber and free to call via this app. The only problem with this apps is that you can’t make a conference call, and only Iphone owner can use this app (beta version for Android user is also available).
Rating : 9/10